Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I'm looking at an approximation of the average speed of seismic wave towards the center of Earth.
The horizontal path of the waves that affects us directly is well documented, but there is not much about the vertical propagation of such waves.

Of course that speed depends upon many factors like

  • depth of the earthquake hypocenter
  • magnitude of the earthquake
  • Earth strata at the hypocenter
  • specific topology of the many layers up to the center of Earth at this location

and this is a complex area, but a rough approximation would be appreciated.
Something like

(speed, validSpeedForThatKilometers) = speedAtDepth(hypoDepth,mag,desiredDepth)

or even better a more complex function that would directly give the rough time to reach depth desiredDepth based on some parameters

time = getTimeToReachDepth(hypoDepth, mag, desiredDepth)
share|cite|improve this question
This link can help you study seismic waves and see that life is not as simple as your thoughts:…. And this gives numbers: – anna v Dec 7 '11 at 5:55
Thanks for the (good) links. I didn't expect formal simplicity, just some rough pointers to match my "simple thoughts" :-) – ringø Dec 7 '11 at 6:39
up vote 3 down vote accepted

The characteristic speed of seismic waves as a function of distance from the center of the earth is represented by reference earth models, such as PREM.

Examples of other reference models are described here.

share|cite|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.